> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cosmos.network/llms.txt
> Use this file to discover all available pages before exploring further.

# Migration

> Move an existing ibc-apps rate limiting integration to ibc-go.

The rate limiting middleware moved from the standalone `ibc-apps` repository into ibc-go. Migrating is a code change across `app.go`. The import paths, the package name, the keeper constructor, and both middleware constructors all change. This guide moves an integration from `ibc-apps` v10 to ibc-go v11.2. For the full current wiring, see [integrate the rate limiting middleware](/ibc/latest/middleware/rate-limit-middleware/integration).

## Update the imports

The module path changes, and the root package is renamed from `ratelimit` to `ratelimiting`.

```diff theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}}
- ratelimit "github.com/cosmos/ibc-apps/modules/rate-limiting/v10"
- ratelimitkeeper "github.com/cosmos/ibc-apps/modules/rate-limiting/v10/keeper"
- ratelimittypes "github.com/cosmos/ibc-apps/modules/rate-limiting/v10/types"
- ratelimitv2 "github.com/cosmos/ibc-apps/modules/rate-limiting/v10/v2"
+ ratelimiting "github.com/cosmos/ibc-go/v11/modules/apps/rate-limiting"
+ ratelimitkeeper "github.com/cosmos/ibc-go/v11/modules/apps/rate-limiting/keeper"
+ ratelimittypes "github.com/cosmos/ibc-go/v11/modules/apps/rate-limiting/types"
+ ratelimitingv2 "github.com/cosmos/ibc-go/v11/modules/apps/rate-limiting/v2"
```

## Update the keeper

The keeper field becomes a pointer. The constructor drops the parameter subspace and the trailing ICS4 wrapper argument, adds an address codec, and moves the authority to the end. It returns a pointer, so drop the dereference.

```diff theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}}
  // app struct field
- RateLimitKeeper ratelimitkeeper.Keeper
+ RateLimitKeeper *ratelimitkeeper.Keeper

  // keeper construction
- app.RateLimitKeeper = *ratelimitkeeper.NewKeeper(
-     appCodec,
-     runtime.NewKVStoreService(keys[ratelimittypes.StoreKey]),
-     app.GetSubspace(ratelimittypes.ModuleName),
-     authtypes.NewModuleAddress(govtypes.ModuleName).String(),
-     app.BankKeeper,
-     app.IBCKeeper.ChannelKeeper,
-     app.IBCKeeper.ClientKeeper,
-     app.IBCKeeper.ChannelKeeper, // ICS4Wrapper
- )
+ app.RateLimitKeeper = ratelimitkeeper.NewKeeper(
+     appCodec,
+     app.AccountKeeper.AddressCodec(),
+     runtime.NewKVStoreService(keys[ratelimittypes.StoreKey]),
+     app.IBCKeeper.ChannelKeeper,
+     app.IBCKeeper.ClientKeeper,
+     app.BankKeeper,
+     authtypes.NewModuleAddress(govtypes.ModuleName).String(),
+ )
```

## Update the v1 wiring

The v1 middleware no longer takes the wrapped app as an argument. Build the stack with `NewIBCStackBuilder`, which injects the underlying app and sets the ICS4 wrapper, replacing the ICS4 argument the old keeper constructor took.

```diff theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}}
- var transferStack ibcporttypes.IBCModule = transfer.NewIBCModule(app.TransferKeeper)
- transferStack = ratelimit.NewIBCMiddleware(app.RateLimitKeeper, transferStack)
+ transferStack := porttypes.NewIBCStackBuilder(app.IBCKeeper.ChannelKeeper)
+ transferStack.
+     Base(transfer.NewIBCModule(app.TransferKeeper)).
+     Next(ratelimiting.NewIBCMiddleware(app.RateLimitKeeper))
+ ibcRouter.AddRoute(ibctransfertypes.ModuleName, transferStack.Build())
```

This example shows a minimal stack. If the chain already runs other transfer middleware, such as packet forward, keep those layers as additional `.Next(...)` calls; only the rate-limiting layer changes.

## Update the v2 wiring

The v2 constructor gains two required arguments, a write-acknowledgement wrapper and the v2 channel keeper, and takes the keeper by value.

```diff theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}}
- transferStackV2 := ratelimitv2.NewIBCMiddleware(
-     app.RateLimitKeeper,
-     transferv2.NewIBCModule(app.TransferKeeper),
- )
+ transferModuleV2 := ratelimitingv2.NewIBCMiddleware(
+     *app.RateLimitKeeper,
+     transferv2.NewIBCModule(app.TransferKeeper),
+     app.IBCKeeper.ChannelKeeperV2,
+     app.IBCKeeper.ChannelKeeperV2,
+ )
+ ibcRouterV2.AddRoute(ibctransfertypes.PortID, transferModuleV2)
```

## Update the app module

`NewAppModule` no longer takes the codec.

```diff theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}}
- ratelimit.NewAppModule(appCodec, app.RateLimitKeeper)
+ ratelimiting.NewAppModule(app.RateLimitKeeper)
```

## Add store upgrades

If rate limiting is being added to a chain for the first time, you must [manually add store upgrades](/sdk/latest/guides/upgrades/upgrade#adding-new-modules-during-an-upgrade) for the new module and configure the store loader to apply them in `app.go`:

```go theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}}
if upgradeInfo.Name == "v11_2" && !app.UpgradeKeeper.IsSkipHeight(upgradeInfo.Height) {
    storeUpgrades := store.StoreUpgrades{
        Added: []string{ratelimittypes.StoreKey},
    }
    app.SetStoreLoader(upgradetypes.UpgradeStoreLoader(upgradeInfo.Height, &storeUpgrades))
}
```

This ensures the new module's stores are added to the multistore before the migrations begin.

## Verify the migration

After the app compiles, confirm the module is active by querying the existing limits.

```bash theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}}
simd query ratelimiting list-rate-limits
```

## Next steps

* Confirm limits behave as expected using the [setting rate limits](/ibc/latest/middleware/rate-limit-middleware/setting-limits) queries.
* Review the full wiring in [integrate the rate limiting middleware](/ibc/latest/middleware/rate-limit-middleware/integration).